Priority is claimed under 35 U.S.C. xc2xa7119 to Japanese Patent Application No. 10-246643 filed in Japan on Sep. 1, 1998, the entire content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a device for changing the attitudes of chips parts, such as electronic chips, by 90xc2x0 while feeding the electronic chips onto a rotor one by one.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 7-157071 discloses a conventional feeding device in which electronic chips are transferred from a parts feeder into a recess formed on the outer periphery of a rotor. The electronic chips are subjected to measurement or the like while being held in the recesses and rotated intermittently. The electronic chips are then transferred from the rotor onto a carrier tape and are loaded therein.
In such a feeding device, since electric characteristics of the electronic chips are measured while the chip parts are being conveyed by the rotor, the electronic chips are placed in the recesses of the rotor in a horizontal position. Measurements are taken by putting measuring terminals into contact with two electrodes of each electronic chip.
FIG. 1 shows an example of such a measuring method, in which P denotes an electronic chip, P1 and P2 denote electrodes, and T1 and T2 denote measuring terminals. Measuring terminals T1 and T2 are arranged in parallel. In such a measuring method a large stray capacitance is produced between the two measuring terminals T1 and T2 which causes errors in measured values.
In order to reduce such errors, it is preferable to take measurements with the measuring terminals T1 and T2 held to both ends of the electronic chip P, as shown in FIG. 2. For this purpose, it is necessary to change the attitude of the electronic chip P in the recess of the rotor from a horizontal position to a vertical position.
Such an attitude changing device is known in which a electronic chip is made vertical by thrusting a pin and by air suction, as is disclosed in Japanese Unexamined Patent Publication No. 7-149422. In this device, however, the electronic chip is liable to be damaged because the thrusting force of the pin acts directly on the electronic chip. Furthermore, since the rotor must be stopped every time the pin is thrust, it is difficult to use this device in a rotor that rotates at high speed. In addition, since high positioning accuracy is needed, the costs of the device increases.
Accordingly, an object of the present invention is to provide an electronic chip attitude changing device that does not significantly damage electronic chips, that is applicable to a rotor which rotates at high speed, and that provides a simple structure at a low cost.
In order to achieve the above objects, according to an aspect of the present invention, an attitude changing apparatus is provided for changing the attitude of an electronic chip, the apparatus includes a rotor including cavities on the outer periphery of the rotor, the cavities contain and hold electronic chips, wherein a part of the electronic chips projects over an outside portion of the rotor; an air suction path for drawing and holding the electronic chips in the cavities of the rotor; driving means for rotationally driving the rotor in a predetermined direction; and a chip guide placed at a fixed position close to the outer periphery of the rotor, the chip guide includes a guide face for making sliding contact with the projecting portions of the electronic chips held in the cavities so as to turn the attitudes of the electronic chips by 90xc2x0.
The chip guide is arranged to face the outer peripheral surface of the rotor, wherein the guide face has an arc guide surface with a first end substantially in the plane of the rotor cavities and a second end substantially perpendicular to the plane of the rotor cavities, the arc guide surface gradually twists between the first end and the second end, and projecting portions of the electronic chips that project toward the outer peripheral surface of the rotor contact the guide face from a loading end of the rotation of the rotor toward a removal end of the rotation of the rotor, whereby the attitudes of the electronic chips are changed from a horizontal position to a vertical position.
The above objects are also achieved, according to another aspect of the present invention by a method for changing the attitude of an electronic chip, by placing an electronic chip in cavities of a rotor, the cavities located on the outer periphery of the rotor, wherein a part of the electronic chips projects over an outside portion of the rotor; by drawing and holding the electronic chips in the cavities of the rotor using an air suction path; by driving the rotor in a predetermined direction; and by making sliding contact to turn the attitudes of the electronic chips by 90xc2x0, by a chip guide placed at a fixed position close to the outer periphery of the rotor, the chip guide including a guide face for making the sliding contact with the projecting portions of the electronic chips held in the cavities.
The above objects are further achieved according to a further aspect of the present invention by an electronic chip feeding apparatus for changing the attitude of the electronic chip including a loading section for loading electronic chips onto a rotor in a first position; a first attitude changing section for slidably changing the position of the electronic chip by 90xc2x0 to a second position, the electronic chip slidably changing from the first position to the second position with the rotation of the rotor; a working section; and a removal section for removing the electronic chips from the rotor.
The projecting portion of the electronic chip held in the cavity of the rotor makes contact with the guide face of the chip guide in conjunction with the rotation of the rotor. Then, the electronic chip starts to turn to a vertical position by the air sucking portion with the rotation of the rotor, and is stably placed in a position turned by 90xc2x0. In this way, since the electronic chip gradually changes its attitude, the impulsive force that is produced by thrusting of the pin does not act, and the electronic chip suffers little damage. In particular, since the air suction path is connected to the cavity that holds the electronic chip therein, the electronic chip is prevented from popping out of, and falling out of the cavity at the time of attitude change, which achieves stable attitude change.
According to one aspect of the present invention the guide face of the chip guide is formed of a smooth and continuous surface in order to reduce friction between the guide face and the electronic chip. Moreover, according to another aspect of the present invention in order to minimize damage to the electronic chip, the guide face is shaped so as not to contact the electronic chip at the edge such that the edge is in face contact with the electronic chip.
In contrast to the pin thrust method, according to the present invention the attitude of the electronic chip is gradually changed with the rotation of the rotor. Therefore, the rotor need not be rotated intermittently, but may be rotated continuously. Accordingly, it is possible to increase the rotation speed of the rotor, and to further improve the throughput in changing the attitude. Furthermore, since a high-precision positioning mechanism is unnecessary, the device is simplified and the cost thereof is low.
The attitude changing device of the present invention is applicable not only to a case in which an electronic chip in a horizontal position is turned to a vertical position, but also to a case in which an electronic chip in a vertical position is turned to a horizontal position. That is, it is possible for the chip guide to be placed to face the outer peripheral top surface of the rotor, for the guide face of the chip guide to be vertical at the loading end rotation of the rotor such that it is in parallel with the inner side faces of the cavities, the guide face of the chip guide is horizontal at the removal end of the rotation of the rotor so as to face the bottom faces of the cavities, and to continuously change from the loading end to the removal end of the rotation of the rotor, and for the projecting portions of the electronic chips that project toward the outer peripheral top face of the rotor to make contact with the guide face from the loading end toward the removal end with the rotation of the rotor, whereby the attitudes of the electronic chips are changed from a vertical position to a horizontal position.
Further objects, features, and advantages of the present invention will become apparent from the following description of the preferred embodiment with reference to the attached drawings.